Real estate near beaches or waterways has a special allure both for residential and commercial purposes. Waterfront property or property located near water is often in high demand for its aesthetic beauty and its many uses from recreation to farming. For example, a large tourist and recreation industry is often built near waterways. In addition, proximity to waterways provides many other advantages, such as convenient shipping and transportation. Most often, the most fertile farming areas are near waterways.
The natural beauty and the many uses of water resulted in constructing commercial and residential buildings near waterfronts. This trend shows no sign of slowing especially as the population grows and every piece of real estate is considered for development. However, real estate near waterways and low lying areas are prone to flooding which displaces people and disrupts businesses as the buildings become uninhabitable and suffer internal damage.
In flood plain areas, conventional buildings 100 are built on an elevated foundation 105 as shown in FIG. 1. Fixed piers 110 are used to permanently elevate the structure 115 to a predetermined height 120 above grade level 125. This allows for floodwater to pass under the structure 115 without actually flooding the structure 115 itself. This traditional flood plain construction is essentially that of a shore-based dock and has been used since early civilization without changes.
The fixed piers 110 are often covered with decorative skirting 130 to hide the relatively unsightly piers 110 and change the appearance of the elevated structure 115 to resemble a non-elevated structure. However, because these buildings are permanently elevated above grade level, it is necessary for visitors and inhabitants to use a large number of steps 135 to access the elevated structure 115. This is a great inconvenience not only to the general population, but also to the infirm, disabled or wheelchair bound.
Other techniques have been proposed for constructing buildings at grade level on dry land. One such technique is disclosed in U.S. Pat. No. 5,347,949, by inventor Paul K. Winston, of Englewood, Colo., hereinafter referred to as Winston. Winston discloses a prefabricated modular housing unit 200 for use in flood prone areas as shown in FIG. 2.
FIG. 2 shows the Winston housing unit 200 floating on floodwater 205. The housing unit 200 uses floatation elements 210 which are made of foam 215 contained in plastic liners 220. The floatation elements 210 are attached below the foundation 225 which is composed of perimeter wooden beams fastened to a conventional floor joist system.
The housing unit 200 is anchored to the building site through a series of extendable piers 230, in combination with a series of wooden pilings 240. The wooden pilings 240 serve as a fixed dry land foundation.
The Winston housing unit 200 is essentially a pontoon-like device wherein the housing unit 200 floats on the floatation elements 210. The Winston housing unit 200 suffers from a number of disadvantages. The extendable telescopic piers 230 are exposed even in the retracted position. Over time, the exposed portions of extendable telescopic piers 230 corrode. This inhibits extension of the telescopic piers 230. Additional corrosion occurs as floodwater rises and the telescopic piers 230 extend. Water even fills the extended telescopic piers 230 to cause a hydraulic locking effect. This washes away any grease and further accelerates corrosion. Further the pontoons of the Winston housing unit 200 will deteriorate over time and do not provide for side loading.
In addition, the Winston housing unit 200 is unstable when it floats and requires careful balancing of loads. On the heavy portion of the housing unit 200, larger foam floatation elements 210 are required. The load distribution in the housing unit 200 shifts as the house is furnished. To compensate for shifting loads, air bladders 250 at each corner of the housing unit 200 are required. The air bladders 250 are filled with proper amounts of air to provide a stable and level floatation. This is complex, inefficient and time consuming as it requires a compressor, a level and fine tuning (i.e., repeatedly inflating and deflating) each air bladder many times to achieve a level floatation. For example, inflating a first air bladder often requires re-adjusting the air in the remaining three air bladders 250, which in turn may necessitate further re-adjustment of the first air bladder.
Furthermore, due to a suction created by floodwater, the pontoon-like Winston housing unit 200 may never float. Due to flood and other concerns, the Winston housing unit 200 and conventional buildings near flood plain areas do not have basements extending below the grade level. Having a basement is a desirable feature in buildings yet lacking in conventional buildings near flood plain areas.
Accordingly, it is an object of the present invention to overcome the disadvantages of the prior art. In particular, it is an object of the present invention to provide a floatable house without extendable posts thus eliminating greasing and extension failures of the posts. Another object of the present invention is to eliminate floatation elements and the need to balance them. It is yet another object of the present invention to provide a watertight basement which floats.
Still another object of the invention is to provide a plurality of pressurized cylinders which can be used to lift the building prior to rising floodwater.